...one can see the transcription & still have no idea on how to pull it off, right?

To me, if you keep your plucking hand in a constant 1/16th note motion(Thumb/down-Pop/up-Thumb/down-Pop/up), you can easily play tunes like "Aeroplane".

To simplify the concept-
In 4/4 time, THUMB the beats om 1 & 3; POP the notes on 2 & 4.
/T...P...T...P.../=all 1/4 notes
/E...G...E...G.../=OPEN strings
/1...2...3...4.../=the count
Now, doubletiming that becomes-
/T.P.T.P.T.P.T.P./
/E.G.E.G.E.G.E.G./
/1.&.2.&.3.&.4.&./=all 1/8th notes
See how the THUMBING now occurs ON THE BEAT & how the POPPING now occurs on the UPBEATS?

If you are having trouble learning the slapped verses by ear, the Libster transcription is very useful...My advice would be to figure out as much of the slap lines as you can and then apply Flea's style to your own improvisations over the same chord changes...This is an awesome song from a bassist's point of view-funky slides, slapped verses, 16th note funk interlude, great fingerstyle solo, and a funky walking line taking it out....